Short-circuiting mechanism



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Dec. 18, 1928. 1,695,789

, c. H. woLFF y S HORT CIRCUITIHG IECHANISI Filed J'nn. 15. 1924 @Mz N. @WR

ATTORNEY Patented Dec. 18, 1928.

UNITED STATES PATENT OFFICE.

CARL H. WOLFF, OF ST. LOUIS, MISSOURI, ASSIGNOR T0 WAGNER ELECTRIC CORPORA- TION, 0F ST. LOUIS, MISSOURI,l A CORPORATION OF DELAWARE.

SHORT-CIRCUITING MECHANISM.

Application filed January 16, 1924. Serial No. 686,505.

My invention relates to a circuit changing mechanism and one ot its important applications is for the reorganizingofthewindingcircuits of an alternating current motor through the agency of centrifugal mechanism, a speappear from the following more detailed de- K scription.

In the accompanying drawings Figure 1 is a front view of a short-circuiting mee'hanism embodying my invention; Figure 2 is a rear view; Figure 3 is a side View; and Figure 4 is a view partly in elevation and partly in cross section, showing the mechanism applied to a motor. v In the form illustrated in the drawings my improved circuit-closing mechanism comprises a supporting "plate 1 secured to'a collar 2, which makes a press fit with the motor shaft 3. At the opposite ends of the suportingplate are formed ears 4 and 5 which orm bearings for the pivotpins 6 and 7. On these pivot ins weightedmembers 8 and 9 aremounted these members comprising U- shaped pieces, to each of which is attached semi-circular weights 10 and 11, each being in the form of half of an annulus and arranged to partially embrace the motor shaft.

Springs 12 tend to hold the weighted members in retracted position. The weights yand springl tension are so proportioned that the weights will move outwardly under the influence of the centrifugal force developed at the 4desired speed. In Figure 4 the weights are shown -in their retracted position, and Figures 1` and 3 illustrate the position of the parts in the circuit-closing position.

Mounted on the free ends ofthe centrifugal members is a circuit-closing disk 1,3Ahaving a central opening for the passage of the rotor shaft. The disk is provided with slots as shown, through which pass the headed pins 14 carried by the centrifugal members. Spacing pieces 16 between the weights and the disk permit the desired relative motions of these parts without interference. The eircuit-closing mechanism is mounted adjacent to the commutator 15, which is provided with a vertical face to be engaged by the resilient Contact pieces formed by slitting the periphery of the short-circuiting disk 13.

As shown in the drawings, the pivot points of the centrifugal members 8 and 9 are spaced away from the motor shaft and are located at a greater distance from the shaft than the point of connection between these members and the short-circuiting disk 13. The arc of outward motion of the centrifugal members is therefore so located that the movement ot these members from retracted posit-ion will impart to the disk a motion longitudinal of the rotor shaft and thereby bring this disk into contact with the ends of the commutator segments when the predetermined critical speed has been attained. It will be understood that the motor is started and brought up to speed by means of current supplied to the brushes 17 which cooperate with the horizontal surface of the commutator.

The inward movement of the weights, under the iniuence of the springs, is limited by the slots in the disk in cooperation with the headed pins 14 and the disk is thus resiliently but firmly held against any tilting movement and prevented from coming into contact with the commutator except under desired condil tions. Simplicity of construction and small number of arts is attained in the arranfrement descri ed by the fact that the centriugal members constitute the sole supporting means for the disk and actuate it in the desired direction without the use of means for changing the direction of motion. l

Having fully described my invention, what I claim as new and desire to secure by Letters Patent ofthe United States is:

1. Circuit changing'mechanism comprising a pivoted centrifugal member, and a circuit-closing member supported by the centrifugal member by means 'of ,a pin and slot connection.

2. Circuit' changing ing a pair of pivoted centrifugal members, a circuit-closing disk mounted thereon, and

mechanism comprisn connections between each centrifugal memn ing a lpair of piVoted centrifugal members, a circuit-closing member carried by said centrifugal members, and means on the centrifugal members and irmly engaging the circuit-closing` member when the centrifugal members are in retracted position to prevent tilting of the circuit-closing member.

4. Circuit changing mechanism compris-V Vmg, the combination of a centrifugal member, a circuit-closing member mounted on the centrifugal member by connectingl means permitting limited Yrelative motion between said parts, the relative positions ot the pivot points of the centrifugal member and its point of connection With the circuit-closing member being such that movement of the centrifugal member from retracted position imparts longitudinal movement to the circuitclosing member.

Circuit changing mechanism comprising the combination With a rotatable shaft, of a support mounted for rotation with the shaft, centrifugal members pivoted to said support on opposite sides of said shaft, and

a circuit-closing disk mounted on said centrifugal members.

6. Circuit changing mechanism comprising the combination with a rotatable shaft, of a support mounted for rotation with the shaft, centrifugal members pivoted to said support on opposite sides of said shaft, and' a circuit-closing membersupported on the icentriugal membersby means of pin and Y slotl connections.

7. Circuit changing mechanism comprisling the combination with a rotatable shaft,

of asupport mounted for rotation with the shaft, centrifugal members piroted to said support on opposite sides ot said shaft, and a circuit-closing disk carried by said centrifugal men'ibers by means of pin and slot connections, said connections beingv arranged to limit the motion ot' the free ends of the centrifugal members toward each other.

8. Circuit changing mechanism comprising the combination with a rotatable shaft,- ot a support mounted 'l'or rotation with the shaft, centrifugal members pivoted to said supporton opposite sides ot said shaft, a

Vcircuit-closing disk carried by said centrifugal members by means of pin and slot connections, said connections being arranged to limit the motion oi the centrifugal members toward each other, and means tending to impel said members toward the shaft.

9. Circuit changing mechanism comprising the combination with a rotatable shaft, ot' a supporting member mounted on the shalt for rotation therewith, centrifugal members pivotally carried by said supporting member and having their tree ends closely' adjacent to the shaft. when in. retracted position, means tending to hold said members in said retracted position, and a circuit-closing member carried by the free ends of said centrifugal members, the pivot points ofthe centrifugal meinbers being at a greater distance from the shaft than the free ends of said members when in retracted position.

In testimony whereof, I have hereunto set my hand this the 12th day of January` 192i.

CARL H. WCLFF. 

